The effect of the position based impedance control（PBIC）system is greatly due to the precision of the inner position controller

and the outer force feedback loop is used to modify the reference position in order to keep the target impedance relationship.Taking the tracking controller as the inner loop of PBIC can enhance the stability and compliance of the system

and can minish the overshoot and tracking error of the system

with the same parameters.There is the experiment result of impedance control of the single finger of HIT/DLR dexterous hand based on joint torque sensor.